Follow us on Twitter and win Autohex II Scan Tool for Kia and Hyundai (worth 945.00 USD)

P1121 Throttle Position Sensor (TPS) Signal Malfunction

AutoHex Online Help: Hyundai TERRACAN(HP) 2006
Component Location
General Description

Driver’s intension to accelerate is transmitted to ECM through Accelerator Pedal Sensor(APS) . And APS, whose mechanism is same as TPS, is required for ECM to determine optimum fuel injection quantity.

As fidelity of APS is strongly required, APS is devided into two. One is APS1, which outputs main signals and the other is APS2, which monitors APS1 performance.

APS1 and 2 do not share power supply and ground. Normally, APS2 output voltage is the half of APS1 and if the ratio of two signal is out of specified value, error is recognized then, Limp Home mode is activated.

When Limp Home mode is activated, engine speed is fixed at 1000RPM and driving performance is limited to prevent excessive power generation due to APS false signal.



DTC Description

The TCM sets this code if an expected low rpm detected.

DTC Detecting Condition

Item

Detecting Condition

Possible Cause

DTC Strategy

? Faulty in APS

? Faulty in APS circuit

? Faulty in TCM/ECM

Enable Conditions

? Always

Threshold Value

? Lower value than specification

Diagnostic Time

? More than 2sec

Fail Safe

? Fail detecting for "INPUT SPEED SENSOR,SOLENOID VALVE" are inhibited.

? Slope control and coast control are inhibited.

Specification

Pedal Released

Pedal Depressed

Sensor Type

APS 1

0.7V~0.8V

3.8V~4.4V

Variable resistance type(Potentiometer)

APS 2

0.275V~0.475V

1.75V~2.35V

Schematic Diagram
Signal Waveform